Grinding wheel dressers for surface grinders



July 7, 1964 D. D. RENFROW GRINDING WHEEL DRESSERS FOR SURFACE GRINDERS Filed June 12, 1962 4 R. 3 .m M Z w :4 3 V m 1 w. a 4 2 DONALD D. RENFEQW AGENT l 0 e 75 3 5 3 2 2$ S k 0 8 V (MQV W 3 4 o M P fl\ 2 O 4 l 2 I 5 9 9 4 m4 2 m j 976 8 2 W B 3 -2 United States Patent 3,139,878 GRINDING WHEEL DRESSERS FOR SURFACE GRINDERS Donald D. Renfrow, 19409 Hatton St., Reseda, Calif. Filed June 12, 1962, Ser. No. 201,895 2 Claims. Cl. 125-11 The invention herein described pertains to a device for dressing the grinding wheel of a surface grinder, and more particularly to one that makes it unnecessary to remove the work in process from the bed of the grinder in order to dress the wheel.

The grinding wheels of surface grinders require repeated dressing, especially if they have been shaped in order to form special grooves in parts that are being fabricated. In the case of most surface grinders, the cutting diamond that is to dress the wheel is mounted on a ferrous block that is placed on the bed or carriage of the grinder where it is held in place by the magnet that normally holds the parts being surface ground, and it is accordingly necessary first to remove the work in process. After the Wheel has been properly dressed or reshaped, it is necessary to put the work in process back on the carriage or bed and to completely realign the work and the wheel with respect to each other. One of the objects of my invention is to make it unnecessary to remove the work in order to dress the grinding wheel.

Another object of my invention is to provide a device of the type described that may readily be attached to existing surface grinders.

A further object is to provide a device of the type described that may readily be attached to the conventional guard that is a part of most surface grinders.

An additional object is to provide a grinding wheel dresser of such structure that it is very easy to move the cutting diamond toward and away from the wheel and to move it parallel to the wheels axis of rotation.

Another object is to provide a device of the type described that is simple in construction, durable and inexpensive to manufacture.

A further object is to provide a design for a surface grinder dresser in which the operating parts, although mounted above the bed or carriage of the grinder, are nevertheless protected and at least partially covered by an appropriate guard.

Still other objects will appear as the specification proceeds.

In the drawings:

- FIG. 1 is a perspective view of a surface grinder equipped with a grinding wheel dresser embodying my invention.

FIG. 2 is a section taken along line 2-2 of FIG. 1.

FIG. 3 is a section taken on line 33 of FIG. 2.

FIG. 4 is a right side view of the assemblyshown in FIG. 2.

The principal components of my device are assembled into a structure that is mounted on a member 1 appropriately secured to the back wall 2 of the complete surface grinding machine, this wall 2 being at right angles to the bed or carriage 3 and to the axis of the grinding wheel 4. The member 1 may be the conventional guard that is usually attached to the surface 2, as shown in FIG. 1, and which surrounds the cutting wheel 4 at a distance therefrom in order to shield the operator and the neighboring vicinity from particles that are thrown tangentially from the periphery of the wheel. If the surface grinding machine is already equipped with such a guard, I prefer that the outer surface of the guard near one of its lower ends be faced as shown at 5 in order to provide a surface that is parallel to the axis of the wheel. This is easily accomplished by facing this portion of the surface at right angles to the back of the guard ice 1 that is mounted against the back wall 2 of the surface grinding machine. If the machine is not already equipped with such a guard, a substitute member may be provided with a first flat surface to mount against the surface 2 and with a second flat surface at right angles to the members first flat side; said second flat surface to be disposed parallel to the axis of the grinding wheel.

In one embodiment of my invention, a rectangqllar block 6 having opposite flat sides 7 and 8 is mounted on the surface 5 of member 1 by means of a pair of shoulder screws 9 and 10 passing through the counterbored clearance holes 11 and 12 in block 6 and threaded into member 1. The guard supplied on some surface grinders is not wide enough for hole 12 to be used to attach block 6, and I accordingly provide an extra counterbored hole 43 to be used instead of hole 12 in such cases. A second block 13, preferably having the same thickness as block 6, is mounted on the lower side of block 6 by means of ways which may appropriately be of the conventional type used on lathes and other equipment having rectilinearly movable components that must be free from play. One such tongue-and-groove arrangement is shown in FIG. 2. In this embodiment, the block 6 is provided with a conventional longitudinal groove having opposite sides 14 and 15 that diverge as they extend away from the bottom surface of the block 6. A tongue 16, which is integral with the second block 13, extends along the top surface of block 13. This tongue has a cross-section resembling a frustum with its base upward, and the opposite sides of this tongue slide against the opposite walls 14 and 15 of the recess provided in block 6.

In order to remove play between the tongue 16 and the walls 14 and 15 of the recess or groove in member 6, I provide a vertical slot 17 in block 6 extending from one end to the other and opening into the recess between the walls 14 and 15. A pair of shoulder screws 18 and 19 pass through suitable clearance holes in block 6 on one side of the slot 17. These screws are then threaded into appropriate female-threaded holes in block 6 on the opposite side of the slot 17. By tightening the shoulder screws 18 and 19, the portions of block 6 on opposite sides of slot 17 are brought together, thus eliminating play in the ways or tongue-and-groove joint, or effectively clamping the parts together as may be desired. A rack 20 with the teeth facing upward, is appropriately attached to block 13, as by screws 21 and 22, passing through clearance holes in the'rack and threaded into block 13, all as illustrated in FIGS. 2 and 3.

In order to move block 13 rectilinearly in either direction as indicated by arrows 23 and 24, in FIGS. 3 and 4 respectively, I provide a gear segment 25 having teeth that mesh with the teeth of the rack 20. The gear segment 25, which has an integral operating handle 26, is

pivotally mounted on a shoulder screw 27, which has a straight enlarged portion 28 between the head of the screw and the threaded end portion 29. The enlarged portion 28 is slightly greater in length than the width or thickness of the gear segment to make sure that the segment does not bind between the head of the screw 27 and the side 8 of the block 6. When the handle 26 is moved to the right or left, as viewed in FIG. 3, the block 13 will move rectilinearly as the teeth of the gear segment 25 push the rack and the lower block 13 longitudinally in one direction or the other.

In order to cover the screws 9, 10, 18 and 19, as well a as the gear segment 25, I provide a channel-shaped cover 30 which I attach to the block 6 by means of screws 31 and 32 which pass through clearance holes in the cover translational movement therethrough at a right angle to the rotational axis of the cutting wheel. Means must be provided for accurately adjusting the longitudinal position of this member with respect to block 13. FIG. 2 shows such an elongated member-the large screw 34, which preferably should have a knurled head 35. The means for accurately adjusting the longitudinal position of this screw consists of its external male threads and the mating female threads in the block 13. A recess 36 extends coaxially into the screw 34 from its outer end 37, and a short cylindrical member or plunger 38 is provided to move freely in the bore 36. The diamond 33 is suitably mounted in the outer end of the plunger or cylindrical member 38. A set screw 39 holds the plunger 38 in a proper position with respect to the cavity or channel 36.

In order to keep the female threads in member 13 in tight engagement with the male threads of the screw 34, I provide member 13 with a horizontal slot 40 extending all the way from said 41 of block 13 to the hole into which the screw 34 is threaded, as shown in FIG. 3. A shoulder screw 42 passes through a counterbored hole 43 extending upward from the lower side of block 13. This screw is then threaded into the portion of block 13 that lies above the slot 40, as best seen in FIG. 3. The tightening of screw 42 of course pulls the upper and lower parts of block 13 together, thus increasing the tension of the female threads in the block against the male threads of the screw, thereby holding the screw 34 in an adjusted position and maintaining the diamond 33 in the precise position to which it has been adjusted for movement axially of the wheel along its periphery.

When the handle or arm 26 of the gear segment 25 is moved to the right or left, as viewed in FIG. 3, the diamond 33 will of course move across the periphery of the wheel in a line parallel with the axis of the wheel. If the periphery of the wheel is to be given a smooth cut all the way across its periphery, this obviously may be done by movement of the handle 26, and if additional passes of the diamond across the wheel are required, the diamond may be moved closer to the axis of the wheel merely by turning the knurled knob 35 of the screw 34 in a clockwise direction.

It will be clear to those skilled in the art that various alterations may be made from the embodiment hereinbefore described and that various parts, components and elements may be substituted for those described and shown, and that they may be transposed and added to, all without departing from the broad spirit of my invention as embodied in the structure set forth in the appended claims.

My claims are:

1. A device for dressing the grinding wheel of a surface grinder having a back wall disposed at a right angle to the bed of the surface grinder and at a right angle to the axis of rotation of said wheel, said device including: a member having two surfaces at right angles to each other, said member having provisions by which it may be so mounted on said wall that one of said surfaces may be disposed parallel to said axis; a first block mounted on said one of said surfaces; a second block mounted on said first block by means of ways for rectilinear movement with respect to said first block and with respect to said axis, said ways comprising (a) a cavity in said first block extending longitudinally of said block and upward and inward from the bottom side thereof and having opposite straight walls diverging from each other as the distance from said bottom side increases, (b) a longitudinally extending slot in said first block opening into said cavity throughout the length of said cavity and of said block, a tongue on the top surface of said second block extending longitudinally thereof and into said cavity, said tongue being integral with said second block and having a crosssection shaped like a frustum with its base upward, the

sides of said tongue contacting the diverging walls of said cavity, and (d) a plurality of shoulder screws passing through clearance holes in said first block on one side of said slot and then threaded into said first block on the opposite side of said slot for adjusting the fit of said ways; a rack attached to said second block and extending parallel to said ways; a gear segment rotatably mounted on said first block and meshing with said rack; an arm attached to said segment whereby it may be manually rotated; an elongated member mounted in said second block for translational movement therethrough at a high angle to said axis; means associated with said elongated member for accurately adjusting its longitudinal position with respect to said second block; and a cutting diamond mounted in the end of said elongated member nearest said wheel.

2. A device for dressing the grinding wheel of a surface grinder having a back wall disposed at a right angle to the bed of the surface grinder and at a right angle to the axis of rotation of said wheel, said device including: a member having two surfaces at right angles to each other, said member having provisions by which it may be so mounted on said wall that one of said surfaces may be disposed parallel to said axis; a first block having a first set of shoulder screws passing through said first block and threaded into said member for mounting said first block on said member with the adjoining sides of said first block and member parallel to the axis of said wheel; a second block mounted on said first block by means of ways for rectilinear movement with respect to said first block and with respect to said axis, said ways comprising (a) a cavity in said first block extending longitudinally of said block and upward and inward from the bottom side thereof and having opposite straight walls diverging from each other as the distance from said bottom side increases, (b) a longitudinally extending slot in said first block opening into said cavity throughout the length of said cavity and of said slot, (0) a tongue on the top surface of said second block extending longitudinally thereof and into said cavity, said tongue being integral with said second block and having a cross-section shaped like a frustum with its base upward, the sides of said tongue contacting the diverging walls of said cavity, and (d) a plurality of shoulder screws passing through clearance holes in said first block on one side of said slot and then threaded into said first block on the opposite side of said slot for adjusting the fit of said ways; a rack attached to said second block and extending parallel to said ways; a gear segment rotatably mounted on said first block and meshing with said rack; an elongated member mounted in said second block for translational movement therethrough at a right angle to said axis; means associated with said elongated member for accurately adjusting its longitudinal position with respect to said second block; a cutting diamond mounted in the end of said elongated member nearest said wheel; and a cover partially enclosing said gear segment and said first set of shoulder screws.

References Cited in the file of this patent UNITED STATES PATENTS 1,463,033 Beckett July 24, 1923 1,545,701 Schramm et a1. July 14, 1925 1,862,379 Koestlin June 7, 1932 2,010,359 Haas Aug. 6, 1935 2,345,821 Kopec Apr. 4, 1944 2,665,680 Gotberg Jan. 12, 1954 2,772,670 Jones Dec. 4, 1956 2,934,057 Weining Apr. 26, 1960 FOREIGN PATENTS 466,667 Germany Oct. 10, 1928 

1. A DEVICE FOR DRESSING THE GRINDING WHEEL OF A SURFACE GRINDER HAVING A BACK WALL DISPOSED AT A RIGHT ANGLE TO THE BED OF THE SURFACE GRINDER AND AT A RIGHT ANGLE TO THE AXIS OF ROTATION OF SAID WHEEL, SAID DEVICE INCLUDING: A MEMBER HAVING TWO SURFACES AT RIGHT ANGLES TO EACH OTHER, SAID MEMBER HAVING PROVISIONS BY WHICH IT MAY BE SO MOUNTED ON SAID WALL THAT ONE OF SAID SURFACES MAY BE DISPOSED PARALLEL TO SAID AXIS; A FIRST BLOCK MOUNTED ON SAID ONE OF SAID SURFACES; A SECOND BLOCK MOUNTED ON SAID FIRST BLOCK BY MEANS OF WAYS FOR RECTILINEAR MOVEMENT WITH RESPECT TO SAID FIRST BLOCK AND WITH RESPECT TO SAID AXIS, SAID WAYS COMPRISING (A) A CAVITY IN SAID FIRST BLOCK EXTENDING LONGITUDINALLY OF SAID BLOCK AND UPWARD AND INWARD FROM THE BOTTOM SIDE THEREOF AND HAVING OPPOSITE STRAIGHT WALLS DIVERGING FROM EACH OTHER AS THE DISTANCE FROM SAID BOTTOM SIDE INCREASES, (B) A LONGITUDINALLY EXTENDING SLOT IN SAID FIRST BLOCK OPENING INTO SAID CAVITY THROUGHOUT THE LENGTH OF SAID CAVITY AND OF SAID BLOCK, (C) A TONGUE ON THE TOP SURFACE OF SAID SECOND BLOCK EXTENDING LONGITUDINALLY THEREOF AND INTO SAID CAVITY, SAID TONGUE BEING INTEGRAL WITH SAID SECOND BLOCK AND HAVING A CROSS- 